Electric furnace with magnetically-rotated charge.



HLN. POTTER.

ELEGTRIG FURNACE WITH MAGNBTIOALLY ROTATED CHARGE. APPLICATION FILED JULY 1, 1905.

975,571 Patented Nov. 15, 1910.

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WITNESSES: INVENTOI? H. N. POTTER. ELECTRIC FURNACE WITH MAGNETICALLY ROTATED CHA RGE.

APPLICATION FILED JULY 1, 1905.

Patented Nov. 15

3 SHEETS-SHEET 2 8) 44,4 ORA/E) H. N. POTTER.

ELECTRIC FURNACE WITH MAGNETIOALLY ROTATED CHARGE.

APPLIOATION FILED JULY 1, 1905.

975,571. 7 Patented Nov. 15, 1910.

& 3 SHEETS-"SHEET 3. W .5

EE Z j/ 7 .J 2 2 a I I .20 M M IN VE N 70/? B)" ZmA EY UNITED STATES PATENT oEEioE.

HENRY NOEL POTTER, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO GEO. WESTING- HOUSE, OF PITTSBURG, PENNSYLVANIA.

ELECTRIC FURNACE WITHMAGNETICALLY-ROTATED CHARGE.

Specification of Letters Patent.

Patented Nov. 15, 1910.

Original application filed July 25, 1904, Serial No. 217,954. Divided and this application filed July 1, 1905.

Serial No. 287,914.

To all whomc't may concern:

Be it known that I, IIENRY Nonn PoTTER, a citizen of the United States, and resident of New Rochelle, county of VVestchester, State of New York, have invented certain new and useful Improvements in Electric Furnaces with Magnetically-Rotated Charges, of which the following is a specification.

In certain electric furnace operations it is desirable to stir a bath offiuid metal while it is maintained at a .very high degree of temperature. Ordinarily mechanical stirring processes cannot readily be practiced under such; conditions of operation and it becomes necessary to resort to other means for accomplishing the stirring of the fluid. I propose to impress upon the mass of fluid metal the effects of a rotating magnetic field, making the fluid the closed secondary of an induction motor. Under these circumstances a rotation or revolution of the fluid will be caused and this revolution of the fluid can be effected in one direction or the other by an appropriate manipulation of the electric currents producing the rotary field. The stirring action can be assisted by giving to the vessel which contains the fused metal an irregular configuration either on the bottom or sides or both, so that the general rotation of the mass will be accompanied by eddies which assist in stirring the fluid. The idea is applicable either to a resistance furnace where the melted metal is itself the resistance or to furnaces either of the are or resistance type in which the melted metal is heated from a source exterior to itself. The molten metal may fill a circular trough, or it may lie on a base in the general form of a disk; or it may constitute an annulus surrounding the lower carbon of an arc furnace, in which the carbons are coaxial and vertical.

The present invention is of wide application, inasmuchas most of the materials produced in electric furnaces are conductors of electricity.

I I have illustrated my invention in the accompanying drawings, in which- Figures 1 and 2 are, respectively, a horizontal and a vertical section of a furnace adapted to perform the functions of the present invention; Figs. 3 and 4, are, respectively, a horizontal and a, vertical section of amodified form of furnace; Fig. 5 is a vertical section of still another modified form of furnace; Figs. 6 and 7 are detail views illustrating parts of the furnace shown in Fig. 5; and Fig. 8 is a diagram of another modification.

In general, it may be stated that the figures are mainly diagrammatic, inasmuch as the invention relates to a broadly conceived invention wherein specific details are of comparative unimportance.

Referring to Figs. 1 and 2, the characters 1 indicates a pool of molten metal surrounded by a container, 10, which may be composed of the mixture from which the molten or fluid metal 1 is produced by the action ofthe furnace. Around the pool 1, at a suitable distance therefrom, such that the temperature conditions do not interfere with theoperation, is located a ring, 2, of laminated ironsurrounded by a conducting coil, 3, from which, at intervals of 120, conductors 4 and 5, branch off and are connected to the collectorrings, 7, 8 and 9, of a three-phase generator, or to the terminals of a three-phase transformer. Fig. 3 illustrates the same general idea as applied to a resistance furnace in which the molten metal 1 is itself the resistance. The current for melting the metal, is applied through terminals, 11, 11, which are supplied with means for water cooling as shown at 12, 12. lVithin or without or underneath the ring 1 is arranged a ring 2 of laminated iron surrounded by a coil 3, as before. In Figs. 3 and 4, the ring of laminated iron is shown as being located within the ring 1 of molten metal. v

In both the forms of furnace hereinbefore described it is possible to set up currents in molten metal which will cause a rotationof the metal or a revolution thereof such as will produce the desired stirring of the metal while it is in a molten state. Such effects are produced by causing currents to flow through the rotary field constitutedby the laminated core, 2 and the conductor, 8. Taking Fig. 3- as an example, the molten metal being kept in circulation, no portion of it remains very long in close proximity to the electrodes, which is in itselfan advantage in addition to the "stirring action. Coming now to the Figs. 5, 6 and 7 we have a similar arrangement in which, however,

' tion furnace in which the melted metal 1 is terminals 4:,

shown in a trough having the shape of a waved ring. The current induced in the ring 1 by a transformer having an iron core, 15, and a primary core, 16. The ring 1 constitutes the secondary and the current induced within it maintains it in fusion. In addition to this three-phase transformer to effect the rotation. This is a ring 2 of laminated iron surrounded by coils 3 and provided with nection with ing.

The directions of the eddy current in the fused metal 1, induced by the three-phase ring, are in general at right angles to the fusing current induced by the transformer 15-16, for which reason, the two do not in-' terfere with each other.

It is obvious that in addition to the alternating current devices s'hown in the drawings, it is possible to produce a direct current the earlier figures of the drawmetal so that the cur-- parallel currents, one.

transformer there is a' 5 and 6, as explained in con-- analogy in the form of a motor, the commutator brushes being represented by water cooled or infusible contacts projecting into the fused mass and serving to transmit therethrough a direct current, preferably of low voltage and extremely heavy amperage. If this current be now out by a constant magnetic field, the entire liquid will rotate or revolve.

In another application filed July 25, 1904, Serial Number 217 ,954, of which this applicationis a division, claims are made upon the apparatus described herein.

I claim as my invention:

l. The method of causing a circulation of conducting molten material in an electric furnace which consists in inducing secondary currents within the body of the molten material and producing a rotating force upon the induced currents by subjecting them to the action of an alternating rotating magnetic field.

2. The method of stirring highly heated, fused, conducting material, which consists in maintaining an alternating rotating magnetic field in inducin relation thereto.

Signed at New ork, in the county of New York, and State of'New York, this th day of June A. D. 1905.

HENRY NOEL POTTER.

GEORGE H. STOCKBRIDGE. 

